The present invention relates to apparatus for filling or refilling containers with flowable media, and more particularly to improvements in apparatus which can be used with advantage for filling and refilling of ink cartridges of the type normally used in cigarette making and analogous machines to supply ink to the so-called printer unit. Printer units are used to apply the brand name, the name of the manufacturer and/or one or more trademarks to the web of cigarette paper or other material which is about to be converted into wrappers of discrete cigarettes or analogous rod-shaped articles of the tobacco processing industry.
As a rule, the cartridge which stores a supply of ink for use in the printer unit of a cigarette maker comprises a cylindrical vessel with a reciprocable piston which can be acted upon to dispense ink at a desired rate when the cartridge is properly inserted in the printer unit. The piston yields when the vessel is in the process of being refilled with ink. Such refilling takes place by way of a nipple which is provided on the front end wall of the vessel and serves to dispense ink in the printer unit in response to forward movement of the plunger.
Heretofore known cartridge filling or loading devices operate not unlike grease guns, i.e., a stream of ink is forced from the spout of the gun into the interior of the vessel by way of the aforementioned nipple whereby the piston yields and advances toward its retracted position, i.e., in a direction away from the nipple. A drawback of such filling devices is that they invariably discharge one or more droplets of ink upon completion of a refilling operation. This results in contamination of the gun, in contamination of the refilled cartridge and in contamination of the surrounding area by a substance which cannot be readily removed. Moreover, the refilling operation is cumbersome and time-consuming, and ink at the discharge end of the gun is likely to incrustate to thus prevent predictable discharge of fresh ink into an empty cartridge.